When you have a hosting package and you create an email address, you may take the option to send and receive messages for granted, but in fact, that isn't always the case. Sending e-mail messages isn't always a part of the web hosting plans that providers have and an SMTP service is needed to be capable to do that. The abbreviation means Simple Mail Transfer Protocol and that is the set of scripts that enables you to send email messages. If you are using an email application, it creates a connection to the SMTP server. The latter then queries the DNS data of the domain, that is a part of the receiving address to find out what mail server manages its emails. After system data is swapped, your SMTP server provides the email to the remote IMAP or POP server and the e-mail is finally delivered in the corresponding mailbox. An SMTP server is necessary if you use some kind of contact page also, so if you use a free of charge hosting plan, for example, it is very likely that you won't be able to make use of such a form as many no charge website hosting providers don't allow outgoing e-mail messages.